Friday, September 1, 2017
Dr. Dawen Li
Department of Electrical and Computer Engineering, Center for Materials for Information Technology
University of Alabama
Hand Lab 1144, 3:30 P.M.
The seminar presentation focuses on two kinds of energy-conversion devices: organic & perovskite solar cells and thermoelectric generators.
In the project on organic polymeric solar cells, the addition of a small amount of PS-b-P3HT diblock copolymer was found to induce favorable P3HT/PCBM active layer morphology in both lateral and vertical directions, and the enhanced P3HT crystallinity facilitate hole transport. We also studied the effect of composition profile on power-conversion efficiency of solar cells.
Due to rapid progress in efficiency, perovskite-based photovoltaics has become a hot topic in renewable energy research. We demonstrated that the incorporation of a particular polymer in perovskite precursors was able to improve stability, and lamp annealing can be employed to attain desired morphology in a much short time as compared to hot plate heating.
In the simulation study of thermoelectric generators (TEGs), various state-of-the-art TE materials spanning a wide temperature range, from 300 K up to 1000 K, have been utilized to build segmented TEG legs. The results reveal that by combining the current best p-type and n-type TE materials, TEG modules could achieve efficiencies of up to 20.9% and output power densities of over 2.1 Watt cm−2 at the temperature difference ΔT = 700 K. In addition, the influence of the thermal radiation, electrical and thermal contact effects have also been investigated. Although considered potentially detrimental to the TEG performance, these effects, if well-regulated, do not prevent segmentation of the current best TE materials from being a prospective way to construct high performance TEGs with greatly enhanced efficiency and output power density.
Dawen Li, an Associate Professor in the Department of Electrical and Computer Engineering at the University of Alabama. Dr. Li received his Ph.D. in Electrical Engineering and Computer Science from the University of Michigan, Ann Arbor, in 2006. During his Ph.D. study, Dr. Li had intern experience at Bell Labs, Lucent Technologies in 2004. From 2006 to 2008 he was a post-doctoral research fellow at the University of Michigan, Ann Arbor. Dr. Li joined the University of Alabama in 2008. He is a recipient of NSF CAREER award. Dr. Li’s current research interest mainly focuses on organic photovoltaics, roll-to-roll printing of perovskite solar cells, and thermoelectrics.
Click here to view more Seminars